1. Field of the Invention
The invention in general concerns read or read and write heads for data storage devices, in particular with an integrated microactuator for fine positioning.
2. Description of Related Art
Due to increasing storage density, the requirements for track following of read-write heads on data tracks on which data are stored digitally, for instance in form of magnetic flux changes, are increasing as well. Read-write heads are used in all magnetic mass storage devices like hard disk drives, diskette drives, and tape files. In case of hard disk drives, a positioner accomplishes the track access to a data track as well as track following thereon. All read write arms are mounted to it, with each write-head arm covering one disk surface. Thereby, the data tracks are arranged concentrically on the disc surfaces. The positioner's actuator is positioned by a servo system such that the respective read-write head in use is guided on a data track. Typically, at any point in time, only one read-write head writes or reads.
With increasing recording density, both the distances between flux reversals as well as the width of the magnetic data tracks are decreasing. For accomplishing the required positioning on the data track, a second stage actuator could be integrated in the read-write head to gain more accurate and higher frequency track following than possible with existing actuators. Concepts for the design of such actuators are known in the art. For a better understanding of these concepts, the detailed design of a read-write arm will be looked at briefly in the following. A read-write arm comprises a read-write head, also called slider, in which a read-write transducer or a read-write element is integrated, which accomplishes magnetic data storage and data retrieval. It further comprises a spring system (suspension). The slider glides at a very small distance over the data surface.
So far, concepts for a secondary actuator consider for instance that a secondary actuation is carried out by the spring system. For such an approach, the spring system is equipped with a positioner, which allows an additional lateral movement of the spring system. Another approach is to integrate a micropositioner between spring system and slider.